Condition Constraints (NUnit 2.4)

ConditionConstraints test a specific condition and are named for the condition they test. They verify that the actual value satisfies the condition. The following condition helpers are provided.

NullConstraint

Action

Tests that a value is Null.

Constructor

NullConstraint()

Syntax

Is.Null

Examples of Use

Assert.That( anObject, Is.Null );
Assert.That( anObject, Is.Not.Null );

TrueConstraint

Action

Tests that a value is true.

Constructor

TrueConstraint()

Syntax

Is.True

Example of Use

Assert.That( condition, Is.True );

FalseConstraint

Action

Tests that a value is false.

Constructor

FalseConstraint()

Syntax

Is.False

Example of Use

Assert.That( condition, Is.False );

NaNConstraint

Action

Tests that a value is floating-point NaN.

Constructor

NaNConstraint()

Syntax

Is.NaN

Examples of Use

Assert.That( aDouble, Is.NaN );
Assert.That( aDouble, Is.Not.NaN );

EmptyConstraint

Action

Tests that an object is an empty string, directory or collection.

Constructor

EmptyConstraint()

Syntax

Is.Empty

Examples of Use

Assert.That( aString, Is.Empty );
Assert.Thst( dirInfo, Is.Empty );
Assert.That( collection, Is.Empty );

Notes

  1. EmptyConstraint creates and uses either an EmptyStringConstraint, EmptyDirectoryConstraint or EmptyCollectionConstraint depending on the argument tested.
  2. A DirectoryInfo argument is required in order to test for an empty directory. To test whether a string represents a directory path, you must first construct a DirectoryInfo.

UniqueItemsConstraint

Action

Tests that an array, collection or other IEnumerable is composed of unique items with no duplicates.

Constructor

UniqueItemsConstraint()

Syntax

Is.Unique

Example of Use

Assert.That( collection, Is.Unique );